In one of the most comprehensive galaxy surveys yet, astronomers have found that galaxies like our Milky Way underwent a stellar “baby boom” churning out stars at a prodigious rate, about 30 times faster than today.
Our sun, however, was a late “boomer.” The Milky Way’s star-birthing frenzy peaked 10 billion years ago but our sun was late for the party — not forming until roughly five billion years ago. The new census provides the most complete picture yet of how galaxies like the Milky Way grew over the past 10 billion years into today’s majestic spiral galaxies.
“It allows us to see what the Milky Way may have looked like in the past. It shows that these galaxies underwent a big change in the mass of its stars over the past 10 billion years, bulking up by a factor of 10, which confirms theories about their growth,” explained Casey Papovich from the Texas A&M University in College Station.
